Process for the manufacture of aldehydes



Patented oetle, 1948 y 2 451 742 UNITED STATES PATENT orrlcr.

PROCESS FOR THE MANUFACTURE E ALDEHYDES Herbert Lindiar, Basel, Swltl'erland, assignor to Hofl'mann-La Roche Inc., Nutley, N. 1., a corporation of New Jersey No Drawing. Application August 13, 1948, Serial No. 44,223. In Switzerland October 14, 1947 1 Claim. (Cl. 260598) 2 The present invention relates to aldehydes and process for the manufacture thereof.

In my co-pending U. S. application Serial Numh 3:034; 0 0 ber 753,379, filed June 7, 1947, it has been shown a B on that an aldehyde may be obtained by condens- 5 III IV ing p-ionone with a halogeno acetic ester while avoiding application of high temperatures and comparatively pure form by condensing p-ionone treating the resulting condensation product with Dehydro-B-ionone fl-metllyl-ionolle an alkaline agent.

According to my said co-pending application R R Serial No. 753,379 the aldehyde 4-(2,6',6'-trimethyl cyclohexene-(l') -y1) -2-methyl butene- (2)-al-(1) may be obtained in high yield and a R R H.

with a halogeno acetic ester while avoiding apv plication of high temperatures, treating the condensation product thus formed with an alkaline Cyclic agent and isolating the aldehyde thus obtained. h rein R may be hydrogen or a methyl" radical. According to d p i fim y be Pseudo-ionone (I) and a-ionone (II) are known condensed th r w th a m n r with a d intermediates usedinthe perfume industry. Dehalogeno acetic ester. The chloro compounds are o-p-ionone (III) is obtained in the usual shown to be especially suitable for the reaction. manner by condensing 2,6,6-trirnethylcyclohexa- In the synthesis s w in t a app ati n. fldiene-(1,3)-al-(1) with acetone. It can also be ionone and a mono-halogeno acetic ester are produced by dehydrogenating fi-ionone according reacted in he presence of n l lin en 5 to one of the usual dehydrogenation methods such as alkali alcoholate, an alkaline earth al- (Houben-Weyl, Methoden der organischen coholate or an alkali amide. Sodium alcoholate, ch mle, ol; 11, year 1925, Leipzig, pages 87-92).

ra y s d um methyiat is shown to be a p-Meth l-ionones (IV) are obtained in accordp ly advantageous condensing agent. The ance with German patent specifications Nos. r t n m y app pr ately be r d out i the 3 127,424, 133,758 and 150,827, whereas the cyclic absence of a solvent, while using excess quantities homologues of the fl-ionone (V) are produced of alcoholate and halogeno acetic ester. There from cyclohexanone or methylcyclohexanone by is also shown the condensation of B- and means of addition of the'elements of acetylene, di-halogeno acetic ester in the usual manner with followed by dehydration, Grignard-condensation magnesium m l m. The Whole sequence of rewith acetic anhydride and partial dehydrogenaactions is disclosed as carried out at a temperatio (Jones and. Richardson, Congress of Pure ur t b e 0 C- and Applied Chemistry, London, Sec. 14, July It has now been found, according to the pres- 17, 1947),

ent invention, that the process of the above-cited The course of the reaction and the particular -P n application a be usefully pp instructions to be followed correspond to those to the manufacture of aldehydes from ketones indicated in co-pending application Serial Numhaving a constitution similar to that of fi-ion'one. her 753,379. The condensation of a said ketone Accordingly, a process for the manufacture of similar to pi-ionone is suitably carried out in the aldehydes is provided, which comprises condensabsence of a, solvent, while employing an excess ing a B-ionone-like ketone, namely an ionone other than fi-ionone, with a halogeno acetic ester ester. The condensation must always be effected n reacting he n nsati n prod t with n under mild conditions. It is advantageous not alkaline agent. s id pr being entirely to isolate or purify the reaction product. Durd out at a temperature net in excess of 50 ing the whole sequence of reactions the tempera- The following keto es ha a constitution ture should not be allowed to rise above 50* 0.

Similar t0 that Of Iii-ionone y typically be used The aldehydes obtained in accordance with the in they present P present process are yellow oils which possess a on. on, on. CH3 double bond in a,fi-p0sitl0ti to the aldehyde group.

They can be purified by means of distillation;

/ -CH=CHC0 CH=CHCO they may further be characterized as phenyl- (33' semicarbazone and thio-semicarbazone as well as CH; CH: by the ultra-violet absorption spectrum. The

- products obtained according to the present proc- I H ess are used-as intermediates in the manufacture Pseudelonm of compounds similar in structure to vitamin A.

of alkali alcoholate and mono-halogeno acetic Example 1 20 parts by weight of pseudo-ionone and 25 parts by weight of chloroacetic acid methyl ester are cooled to -10 C. while stirring. 15 parts by weight of dry, pulverized sodium methylate are added in small portions. During this operation the reaction temperature is kept between and C. After the last portion has been added, stirring is'continued for 4 hours while cooling. 60 parts by volume of '15-per cent. solution of sodium hydroxide in methanol are then added and stirring is continued for further two hours. 90 parts of water are added and the mixture is extracted with ether; then the solvent is evaporated, and the mixture is fractionated in vacuo. 12 parts by weight of pure aldehyde of B. P. mm. Hg 140-142 C. are obtained n =1.508.

The phenyl-semicarbazone melts at 147 C. and shows a depression of the melting point of more than 20 C. when mixed with the phenyl-semicarbazone of pseudo-ionone having the same melting point. The ultra-violet absorption spectrum shows an absorption maximum at 230 m Example 2 20 parts by weight of a-ionone are reacted with 26 parts by weight of mono-chloro-acetic acid ethyl ester and 13.5 parts by weight of pulverized sodium ethylate, as described in Example 1. The mixture is then saponifled, diluted with water andafter allowing it to stand for several days-extracted with ether. The etherfractions are worked up as described in Example 1. Thus a-aldehyde is obtained in good yield. The product corresponds to the aldehyde described by I. M. Heilbron and his collaborators in the Journal of the Chemical Society, London, year 1942, vol. II, page 732.

I claim:

Process which comprises condensing an ionone, other than fl-ionone, and having the characteristic side chain (lower alkyl) with a halogeno acetic ester, and reacting the condensation product with an alkaline agent to produce a corresponding butene-(2) al-(i) having the characteristic corresponding side chain --CHz--CH=C(lower alkyl)-CHO,

said process being entirely carried out at a temperature not in excess of C.

HERBERT LINDLAR.

No references cited.

Patent No. 2,451,742.

HERBERT LINDLAR It is hereby certified that errors appear in the printe numbered patent requiring correction as follows:

Column 4, lines 16 to 18 inclusive, for the formula 0 ormon-ll" line 19, strike out (lower alkyl) and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 8th day of March, A. D. 1949.

d specification of the above THOMAS F. MURPHY,

Assistant Uommiuimr of Potato.

0 read -oH=oH-ll (Iowa! alkl 

